A motor control system generates pulse width modulated signals to drive a control circuit to power a permanent magnet (PM) motor. The control circuit has several pairs of transistors where each pair of transistors (e.g., first and second transistors) is electrically coupled in series to one another. Further, a period between de-activating the first transistor and activating the second transistor is known as a “dead-time interval.” Without the dead-time interval, the first and second transistors would conduct at the same time and cause a relatively high current to flow through the first and second transistors from a voltage source to electrical ground without current flowing through a motor winding.
A problem with the above motor control system is that the system utilized a static non-changeable dead-time interval. Further, because the system is unable to adjust the dead-time interval, undesirable torque ripple can occur in a motor during certain commanded torque conditions.
Accordingly, the inventors herein have recognized a need for an improved system and method that can adjust a dead-time interval between de-activating a first transistor and activating a second transistor in a motor control circuit.